Penrose splines could be smoother

[gordonwoodhull]

I used simple splines with the two control points set equal, because these are easy to understand. The spline is confined to a triangle formed by the three points, and tangent to two of its legs.

The points of the triangle are the center of the tile, the end of the “symbol”, and the point where the line between symbol arm ends on the two tiles intersects with the edge between them.

The final slope of the arm of one tile is the same as the starting slope of the arm on the next tile, but I think it would be smoother if the velocity of the spline going through the tile edge is the same on both sides.

IIUC this means the two control points should remain on the sides of the triangle, but their distance from the center point and edge point should be a constant. You can see this in vector drawing programs where the magnitude and direction of control points across an end point and into the next segment are mirrored.